Endoscopic Ultrasound-guided Tissue Acquisition of Pancreatic Malignancy: A Retrospective Study at a Tertiary Center.

Background: Endoscopic ultrasound (EUS) is gaining ground in today's diagnostic routine due to its ability to provide dynamic, accurate representations, but mostly because it facilitates tissue sampling amenable to histopathologic studies. Our main objective was to assess the accuracy of sampling pancreatic malignancies through EUS-fine-needle aspiration (FNA) compared to EUS-fine-needle biopsy (FNB) at a tertiary referral center, where rapid on-site evaluation (ROSE) for EUS-FNA is not available.

Material and methods: A retrospective, 5-year analysis of all EUS-guided tissue acquisitions of pancreatic masses suggestive of neoplasia was performed. Out of the 484 patients who initially underwent non-invasive imaging studies, 401 subjects were ultimately confirmed as malignant using EUS-FNA/FNB or surgery.

Results: Overall, the accuracy of EUS-guided sampling was 91%. There were 36 patients (9%) with false-negative results after EUS, who were further addressed to surgery and confirmed with pancreatic malignancy. Cytological and histological examinations found that FNB was significantly higher than FNA regarding the diagnostic yield (91.3% vs. 84.1%; p-value<0.05). Moreover, FNB required fewer needle punctures than FNA to achieve a definitive diagnosis (1.63 vs. 1.99; p-value<0.05).

Conclusions: Diagnostic management of pancreatic malignancies is unequivocally improved by FNB needles, rendering an improved tissue acquisition at a lower number of passes.